Gastrointestinal aspirator pump

ABSTRACT

The gastrointestinal pump, preferably an aspirator, includes means for creating positive and negative pressures. A timer circuit, in conjunction with an arrangement of valves, activates the positive and negative pressure outputs of the pump in a selectable, alternately timed sequence. A double lumen tube transmits the pressures to the gastrointestinal tract. The negative pressure lumen withdraws the gastric fluids, while the positive pressure lumen exerts force at the opening of the negative pressure lumen to prevent blockage of the opening. A collecting vessel is connected in the negative pressure line. The lumens of the tube may be eccentrically or concentrically located. Openings may also be formed along the length of the double lumen tube.

[451 May 27, 1975 United States Patent [191 Ross [ GASTROINTESTINALASPIRATOR PUMP [76] Inventor: John R. Ross, 370 Clyde St.,

Brookline, Mass. 02167 [22] Filed: Feb. 20, 1973 [2]] Appl. No.: 333,871

[52] US. Cl 128/278; 128/350 R; 128/240 [51] Int. Cl A6lm l/00 [58]Field of Search 128/240, 276-278, 128/34835O [56] References CitedUNITED STATES PATENTS 1,928,992 10/1933 Clark et a1. 128/349 R 3,066,67212/1962 Crosby, Jr. et a1. .1 128/276 3,142,298 7/1964 Koski et a1128/276 3,347,235 10/1967 I-Iunnicutt..... 128/276 3,429,313 2/1969Romanelli 128/276 3,626,928 12/1971 Hohokus et a1 128/276 3,702,11511/1972 Elcaness 128/276 FOREIGN PATENTS OR APPLICATIONS 191,092 5/1937Switzerland 128/348 [57] ABSTRACT The gastrointestinal pump, prefierablyan aspirator, in-

cludes means for creating positive and negative pressures. A timercircuit, in conjunction with an arrangement of valves, activates thepositive and negative pressure outputs of the pump in a selectable,alternately timed sequence. A double lumen tube transmits the pressuresto the gastrointestinal tract. The negative pressure lumen withdraws thegastric fluids, while the positive pressure lumen exerts force at theopening of the negative pressure lumen to prevent blockage of theopening. A collecting vessel is connected in the negative pressure line.The lumens of the tube may be eccentrically or concentrically located.Openings may also be formed along the length of the double lumen tube.

150,667 4/1904 Germany ..128/240 4Claims,5Drawing Figures l4 16 lo 4&6)56$ @se l8 5 5 LT? 2- I I 2 l 2B 20 48 so 52 54 POWER S-A +PC u FIG. 2

FIG. 5

POWER SWITCH POWER SOURCE SWITCH JUL - TIMER OR PRESSURE -P JL DURATIONDURATION SWITCH SWITCH CONTROL \52 GASTROINTESTINAL ASPIRATOR PUMPBACKGROUND OF THE INVENTION This invention relates to a gastrointestinalpump and, more particularly, to an aspirator that avoids blockage of thenegative pressure tube in the gastrointestinal tract.

Gastrointestinal aspirators are commonly used for withdrawing the fluidcontents of the gastrointestinal tract.

One type of a known aspirator utilizes a single lumen tube fortransmitting a negative pressure from the aspirator to thegastrointestinal tract. The negative pressure in the tube withdraws thecontents.

One drawback with this type of aspirator resides in the tendency of thetube opening to become blocked by gastrointestinal membranes and debris.The blockage not only impedes effective aspiration but also may causesevere pain and discomfort to the patient. In cases where the intestinalwall becomes drawn to or into the suction opening, the tube cannot bemoved within the digestion tract without release of the vacuum.

Known attempts to solve the problem have either not been successful orhave been only partially effective and with the loss of other desirablefeatures. In one conventional aspirator, the tube has a plurality ofholes along its length so that if some openings are blocked, others mayremain open, However, such an aspirator does not entirely prevent theundesirable blockage or attachment to the intestine. Additionally, itmay be impossible with such a tube to reach certain parts of thegastrointestinal tract, or to identify the exact location in the tractfrom which a sample was taken.

Another known arrangement utilizes a hood at the end of the tube, thehood having a plurality of openings to permit gastrointestinal fluids toenter the hood, from which they are drawn into the tube. The hood alsois provided with an air-tight compartment connected to another tube insuch a way that air may be pumped into the compartment to extend thehood to keep the hood erect. Such an aspirator, however, does notentirely prevent blockage and is difficult to position in certain partsof the gastrointestinal tract.

Also known is an aspirator that sequentially supplies a positive andnegative pressure to the tube, the gastrointestinal contents beingwithdrawn during the negative cycle, with the positive pressure intendedto prevent blockage of the tube opening. With such a device, however,the blockage is removed only during the positive cycle with variable andirretrievable loss of fluids that are being forced back into thegastrointestinal tract, and blockage can occur before new fluid has beenwithdrawn. Therefore, the return of fluids to the gastrointestinal tractprevents accurate analysis. Important diagnostic information can beobtained from knowledge of the exact location in the tract from which agiven sample is taken. However, if the tube contents are alternatelypushed forward and backward in the tube, the identity of the location ofa given portion of the sample can become confused or lost.

Thus, it is an object of the present invention to provide agastrointestinal aspirator that prevents tube blockage, that operatesefficiently and safely, that requires a minimum of time on the part ofattendant personnel, and that accurately permits physicians to determinethe location in the gastrointestinal tract from which samples areremoved. Additional objects will ap pear as the description proceeds.

SUMMARY OF THIE INVENTION There is provided in accordance with thepresent invention, a gastrointestinal aspirator that accomplishes theabove objects. In the aspirator of the present invention, means areprovided for withdrawing gastrointestinal fluids through a suction tubeand for preventing blockage of the opening of the suction tube in amanner independent of the passage of the contents through the suctiontube. Thus, continuous operation and change of position are possiblewithout attachment to the intestinal wall and the exact location in thegastrointestinal tract from which the fluids are withdrawn can beidentified. Blockage of the tube inlet is prevented by injecting airinto the intestine through a separate tube, having its openingpositioned near to the opening of the suction tube. In this way, an airbubble is formed so as to lift blocking membranes or debris adjacent tothe tube and thereby free the suction tube opening. Preferably, thepositive and negative pressure cycles occur alternately.

In one form of the present invention, a single pump provides both thepositive and negative pressures. The pump may be controlled by a timerthat causes the pump to supply positive and negative pressuresalternately. The duration of each pressure cycle is variable and mayrange from 10 to 0.1 seconds.

The two tubes are preferably joined to form a double lumen tube whichpermits the aspirator to operate more efficiently and facilitatesinsertion and positioning. The lumens may be either eccentrically orconcentrically arranged, and may also be formed with openings alongtheir lengths to provide a plurality of openings for withdrawing thefluids and for air injection.

Pressure, temperature, and/or pH sensing elements may be provided in thetube, for diagnostic purposes or to monitor and control the positive andnegative pressures. Thus, if the pressure tends to exceed a safe limit,control elements can be activated to maintain the pressure within thesafe range.

A vessel for collecting the gastric fluids may be inserted in thenegative pressure line.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of thegastrointestinal aspirator according to the present invention;

FIG. 2 is a sectional view of the double lumen tube taken along thelines 2-2 of FIG. 1;

FIG. 3 is a view of an alternate form of a double lumen tube;

FIG. 4 is a sectional view of a triple lumen tube;

FIG. 5 is a schematic diagram of the aspirator.

DESCRIPTION OF PREFERRED EMBODIMENTS In an exemplary embodiment of agastrointestinal aspirator according to the present invention, as shownin FIG. 1, the aspirator includes a control mechanism indicatedgenerally at 10, a positive pressure line 12, negative pressure lines 14and 16, a vessel 18 for gastrointestinal fluids, and a double lumen tube20. The control mechanism 10 operates to provide a negative pressure orsuction to cause the gastrointestinal fluids to be withdrawn throughline 16 and collected in the vessel 18. Positive pressure is provided inthe line 12 for blockage prevention as will be described.

In the double lumen embodiment of FIG. 2, a tube 20 is provided with alumen 22 for positive pressure and a lumen 24 for negative pressure. Thetube 20 may be made of rubber, PVC, polyethylene, or other similarflexible materials. A wall 26 in the tube 20 forms a barrier between thetwo lumens 22 and 24. Openings 28 are provided in lumen 22 for supplyingair under positive pressure to the gastrointestinal tract. Openings 32are provided in the negative pressure lumen 24, to permit the fluids tobe withdrawn through lumen 24 to the vessel 18. The emission of airunder positive pressure adjacent to the negative lumen openings 32prevents blockage by lifting the adjacent membranes. In this way abubble of air is formed, and during the negative cycle, it will enterthe negative lumen 24, but such air in the negative lumen does no harmand merely passes along to the vessel 18 and thence to exhaust. Theopenings 28 and 32 may be arranged in closely spaced pairs along asubstantial length of the tube 20, or a single pair may be located atthe endof the tube adjacent to a metallic slug to permit locationidentification by X-ray. The holes can be on opposite sides of the tubeas shown in FIG. 2, but in that case, a solid object caught in thenegative opening 32 may not be freed by the bubble. For this reason,placing the holes side-by-side as indicated by arrows 29 and 33 with theholes occupying the position shown in dotted lines, may be preferred. InFIG. 3 a form of muIti-lumen tube is shown in cross-section, with apositive pressure tube 36 inside a negative pressure tube 38 and withwebs 40 and 42 maintaining the concentric spacing, but in this case thepositive pressure openings 28 are inside of and in alignment with thenegative pressure openings 32. By this arrangement, when air is ejected,during the positive cycle, it passes outwardly through the negativeopening 32 into the gastrointestinal tract so as to relieve blockage inthe negativeopenings 32. Fluid back-pressure in the negative pressurelumen 24 prevents the air from following the negative lumen rather thanpassing out into the tract. In this way, blockage even by a looseparticle is prevented. A fourth lumen 92 (see FIG. 4) can be provided tohouse filaments connected to pressure, pH, and temperature sensinginstruments positioned appropriately in the tube.

The control mechanism has indicators and controls for operation of thegastrointestinal aspirator. A positive pressure gauge 44 provides avisual indication of the positive pressure. Similarly, a pressure gauge46 provides an indication of the negative pressure. These gauges areeach provided with an adjustable maximum safe pressure switchcontrolling an alarm (not shown) which will be rung if the safe pressureis exceeded. A switch 48 activates power to the control mechanism. AnActivate-Standby control 50 operates to control the supply of pressuresto the lumens of tube 20. A pressure control 52 determines whetherpositive and negative pressures are applied alternately through thelumens of tube or only negative pressure is applied through lumen 24. Aswitch 54, designated as manual purge", permits a constant positivepressure to be provided through lumen 22 into the gastrointestinaltract. A positive pressure time duration switch 56 is provided to selectthe time duration of the positive pressure cycle. Similarly, a negativepressure time duration switch 58 is provided to control the duration ofthe negative pressure cycle.

FIG. 5 diagramatically illustrates the operation of the controlmechanism 10. Power to operate the aspirator is provided through thepower switch 48 from a source 59, which may be a standard outlet powerof I20 volts, 6O hz. The power switch 48, when activated, provideselectrical power to operate a pump 60, a timer control 62, solenoids forvalve control, lights, warning buzzers, etc. The pump 60 is preferably apositive displacement pump of the piston or rotary types. A negativepressure line 62 and a positive pressure line 64 are provided for pump60. When the pump 60 is of the piston type, both lines 62 and 64 may beprovided on the same side ofthe piston with appropriate check valvesvLines 62 and 64 can also be arranged on either side of the piston withslight modification to the arrangement of FIG. 5. When the pump 60 is ofthe rotary type, the outputs are preferably arranged on either side ofthe rotating members.

The following description relates to the arrangement of the elementsconnected to lines 62 and 64. The negative pressure line 62 passesthrough a check valve 66 that only permits air to pass into the pump 60.Line 62 then leads to a valve 68, shown as a cylinder valve. Variousforms of valves suitable for this purpose are available commercially.Similarly, the positive pressure line 64 leads to valve 68 through acheck valve 76 that only permits air to pass out of the pump. The valve68 includes portions for separately valving the positive and negativelines. Valve 68 is controlled by solenoid mechanism (not shown),energized by operation of the Standby-Activate switch 50 in the controlmechanism 10. In operation, with the standby-activate switch on, bothpositive and negative pressures are permitted to pass through the valve68. This is the position of the valve depicted in FIG. 5. When thestandby-activate switch is off, or in the standby position, the valve 68is positioned to connect the positive and negative outputs to theatmosphere and the pump will then operate without load.

The negative pressure line 62 then leads from the valve 68 to a pressurereducing valve 72 and also branches off to a pressure relief valve 74.Similarly, the positive pressure line 64 leads to a pressure reducingvalve 76 and a pressure relief valve 78. The pressure relief valves areadjustable and provide a bleed-off to prevent the pressure fromexceeding a selectable limit. The pressure reducing valves, alsoadjustable, may provide a means for setting the amount of positive andnegative pressures. In the present context, I employ only 1 psi. maximumpressure on each line.

The positive and negative lines next pass to a valve 80 that iscontrolled through a solenoid 82 by the timer 62. Valve 80 has twopositions. In the position shown in FIG. 5, the negative pressure isbeing transmitted to lumen 24 of the tube 20, while the positivepressure is being transmitted to the atmosphere. When the valve 80 is inits alternate position, the negative pressure line is connected to theatmosphere and the positive pressure line to lumen 22 of the tube 20.The valve 80 is shown being controlled by solenoid 82 which in turn iscontrolled by either a signal from the timer 62 or by a signal from themanual purge switch 54.

The output from the timer 62 is provided to the solenoid 82 over a line61. The purpose of the timer 62 is to provide a time duration for thegeneration of negative and positive pressure cycles. This is controlledby negative and positive duration switches 58 and 56 respectively. Thedetails of the timers are standard and are not shown herein. Simpleadjustable clock timers are available commercially to perform thefunctions described, and they form no part of the invention inthemselves. In the present embodiment, the time durations areindependently selectable on the positive line from I to seconds, and onthe negative line from 0.1 to 10 seconds. The switches 56 and 58 areprovided with control points calibrated for these durations. Fordurations in the range of l to 10 seconds, the timer may comprise anelectro-mechanical timer. For shorter durations, such as 0.1 seconds, itis preferable to provide a digital clock or an adjustable RC timernetwork. In operation, the timer provides an energizing signal forsolenoid 82 corresponding to the selected duration of the positivepressure cycle and provides no signal to the solenoid 82 for the timeinterval of the negative pressure cycle, the valve 80 being moved to thenegative pressure position by spring action.

The negative pressure line from valve 80 leads to negative pressuremeter 46 and then to the vessel 18. The positive pressure line leads toa positive pressure control valve 86 and then to the positive pressuremeter 44. The valve 86, when activated by the positive pressure controlswitch 52, exhausts the positive pressure air to atmosphere. Its primarypurpose is to provide a quick method for interrupting positive pressurein the event of failure of the relief valve 78.

In operation, there is no operation of the aspirator when the switch 50is in standby. In this position, the valve 68 provides a bleed-off forboth the negative and positive pressure lines and thereby prevents anypressure from being transmitted to the lumens of tube 20. The pump 60 isthen operating under a no-load condition, and the check valves 66 and 76permit air to enter and leave the pump 60.

During the normal operating cycle of the aspirator, an alternatepositive and negative pressure is provided. Here the activate-standbyswitch 50 is in the activate position which controls the valve 68 topermit continuous positive and negative pressures to be supplied to thevalve 80. During the positive pressure cycle determined by the timer 62,the solenoid 82 is energized and the valve 80 is placed in the positionwherein positive output is provided to lumen 22 of the tube and thenegative line is open to the atmosphere. Air for the pump 60, which isrequired to generate the positive pressure, is supplied through thenegative pressure line, which permits the air to pass the valve 80, thepressure reducing valve 72, the valve 68, and the check valve 66. Duringthe duration of the negative pressure cycle, the timer 62 deactivatesthe solenoid 82 and, by spring return action, places the valve 80 in theposition shown in FIG. 5. The pump 60 draws air from lumen 24 of thetube 20 through the vessel 18, the valve 80, the pressure reducing valve72, the activate-standby valve 68 and the check valve 66.

The normal cycle is interrupted when the positive pressure controlswitch 52 is selected. Here, the valve 86 causes the positive pressureoutput to bleed off so undesirable pressures from building up in thegastrointestinal tract. During operation of this mode, a bubble of airbuilds up in the intestine creating positive pressure which forcesfluids up through lumen 24. There is no suction on lumen 24 is this modebecause the negative line is open to the atmosphere at valve 80, makingit a pump not an aspirator.

The primary feature of the present invention is accomplished bypreventing blockage of the openings of the negative pressure lineindependently of that line, and without reversing the direction of flowof fluids in the negative line.

In operation, a small bubble is injected into the digestive tractadjacent to the negative orifice, and by lifting the surroundingmembranes, frees blockage. During the negative cycle, the bubble issucked into the negative line, but with it also comes fluid. Thereafter,if the negative cycle is continued, intestinal membranes or debris mayplug the openings, but the timing sequence can be selected to stop thenegative cycle at that point, and reactivate the positive cycle for ashort period. Part of the positive pressure bubble may escape from thearea of the negative pressure opening and rise in the tract, but thiscauses no problem because any gas under pressure in the tract canreadily be drawn off into the negative lumen 24 by moving the openingsaround to expose them to the gas. Of course, motion of the tube 20 isnot impeded because of the constant freeing action of the positivecycle.

The embodiments of the present invention are intended to be merelyexemplary and those skilled in the art will be able to make numerousvariations of them without departing from the spirit of the presentinvention. All such variations and modifications are intended to bewithin the scope of the present invention as defined in the appendedclaims.

I claim:

1. An aspirator-pump and tube combination for evacuating liquid from anintestinal cavity wherein debris or tissue can block the evacuatingmeans comprising:

a. air pump means with connections to supply both positive and negativepressure (relative to atmospheric) air;

b. a multi-lumen tube adapted to be inserted into said cavity having apositive air pressure lumen connected to the positive air connection ofsaid pump and a negative pressure lumen connected to the negativepressure connection of said pump;

c. means including valves and a timer for supplying positive pressureair from said pump to said positive air pressure lumen for a measuredperiod of time;

d. means for withdrawing liquids from said cavity comprising wallsforming a negative pressure opening in said negative pressure lumencommunicating with said cavity, and

e. means for moving debris or tissue away from said negative pressureopening comprising walls in said positive air pressure lumen forming apositive air pressure opening, and additional walls supporting saidpositive air pressure opening in position to project air against saiddebris or tissue blocking the negative pressure opening during saidperiod.

2. The aspirator-pump and tube combination according to claim 1including additional negative and positive pressure openings spacedalong said tube.

3. The aspirator-pump and tube combination, according to claim 1 whereinsaid positive and negative pressure lumens are parallel tubes.

4. The aspirator-pump and tube combination of claim I wherein saidpositive pressure lumen is within said negative pressure lumen.

1. An aspirator-pump and tube combination for evacuating liquid from anintestinal cavity wherein debris or tissue can block the evacuatingmeans comprising: a. air pump means with connections to supply bothpositive and negative pressure (relative to atmospheric) air; b. amulti-lumen tube adapted to be inserted into said cavity having apositive air pressure lumen connected to the positive air connection ofsaid pump and a negative pressure lumen connected to the negativepressure connection of said pump; c. means including valves and a timerfor supplying positive pressure air from said pump to said positive airpressure lumen for a measured period of time; d. means for withdrawingliquids from said cavity comprising walls forming a negative pressureopening in said negative pressure lumen communicating with said cavity,and e. means for moving debris or tissue away from said negativepressure opening comprising walls in said positive air pressure lumenforming a positive air pressure opening, and additional walls supportingsaid positive air pressure opening in position to project air againstsaid debris or tissue blocking the negative pressure opening during saidperiod.
 2. The aspirator-pump and tube combination according to claim 1including additional negative and positive pressure openings spacedalong said tube.
 3. The aspirator-pump and tube combination, accordingto claim 1 wherein said positive and negative pressure lumens areparallel tubes.
 4. The aspirator-pump and tube combination of claim 1wherein said positive pressure lumen is within said negative pressurelumen.